<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			body{
				display: flex;
				justify-content: center;
				align-items: center;
				margin: 0;
				height: 100vh;
				background: #000;
			}
			.box{
				width: 200px;
				height: 200px;
				/* 背景色渐变 */
				background: linear-gradient(45deg,transparent,transparent 50%,yellow,orange);
				border-radius: 50%;
				position: absolute;
				animation: animate 1s linear infinite;
			}
			@keyframes animate{
				0%{
					transform: rotate(0deg);
					filter: hue-rotate(0deg);
				}
				100%{
					transform: rotate(360deg);
					filter: hue-rotate(360deg);
				}
			}
			.box::before{
				content: '';
				position: absolute;
				top:15px;
				bottom: 15px;
				left:15px;
				right: 15px;
				background: #000;
				border-radius: 50%;
			}
			.box::after{
				content: '';
				position: absolute;
				top:0;
				bottom: 0;
				left:0;
				right: 0;
				background: linear-gradient(45deg,transparent,transparent 50%,yellow,orange);
				border-radius: 50%;
				z-index: -1;
				filter: blur(30px);
			}
		</style>
	</head>
	<body>
		<div class="box"></div>
		<!-- 
			弹性布局
				body{
					display: flex;
					justify-content: center;
					align-items: center;
					margin: 0;
					height: 100vh;
				}
				background: linear-gradient(45deg,transparent,transparent 30%,yellow,orange,#fd1234);
				border-radius: 50%;
				width: 200px;
				height: 200px;
				before
				after
		-->
	</body>
</html>
